共查询到20条相似文献,搜索用时 15 毫秒
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Daniel T. Baran John M. Quail Rahul Ray Thomas Honeyman 《Journal of cellular biochemistry》2001,80(2):259-265
We have recently reported that annexin II serves as a membrane receptor for 1α,25‐(OH)2D3 and mediates the rapid effect of the hormone on intracellular calcium. The purpose of these studies was to characterize the binding of the hormone to annexin II, determine the specificity of binding, and assess the effect of calcium on binding. The binding of [14C]‐1α,25‐(OH)2D3 bromoacetate to purified annexin II was inhibited by 1α,25‐(OH)2D3 in a concentration‐dependent manner. Binding of the radiolabeled ligand to annexin II was markedly diminished by 1α,25‐(OH)2D3 at 24 μM, 18 μM, and 12 μM and blunted by 6 μM and 3 μM. At a concentration of 12 μM, 1β,25‐(OH)2D3 also diminished the binding of [14C]‐1α,25‐(OH)2D3 bromoacetate to annexin II, but cholecalciferol, 25‐(OH)D3, and 24,25‐(OH)2D3 did not. Saturation analyses of the binding of [3H]‐1α,25‐(OH)2D3 to purified annexin II showed a KD of 5.5 × 10−9 M, whereas [3H]‐1β,25‐(OH)2D3 exhibited a KD of 6.0 × 10−9 M. Calcium, which binds to the carboxy terminal domain of annexin II, had a concentration‐dependent effect on [14C]‐1α,25‐(OH)2D3 bromoacetate binding to annexin II, with 600 nM calcium being able to inhibit binding of the radiolabeled analog. The inhibitory effect of calcium was prevented by EDTA. Homocysteine, which binds to the amino terminal domain of annexin II, had no effect on the binding of the bromoacetate analog to the protein. The data indicate that 1α,25‐(OH)2D3 binding to annexin II is specific and suggest that the binding site may be located on the carboxy terminal domain of the protein. The ability of 1β,25‐(OH)2D3 to inhibit the binding of [14C]‐1α,25(OH)2D3 bromoacetate to annexin II provides a biochemical explanation for the ability of the 1β‐epimer to inhibit the rapid actions of the hormone in vitro. J. Cell. Biochem. 80:259–265, 2000. © 2000 Wiley‐Liss, Inc. 相似文献
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P H Stern H F DeLuca N Ikekawa 《Biochemical and biophysical research communications》1975,67(3):965-971
R and S isomers of 24-OH-D3 and 24,25-(OH)2D3 were tested for their effects on bone resorption . 24(R), 25-(OH)2D3 was more active than 24(S),25-(OH)2D3. Likewise, 24(R)-OH-D3 was more active than 24(S)-OH-D3. The bone resorbing activity of 24(R)-OH-D3 was equivalent to that of 25-OH-D3; 24(R),25-(OH)2D3 was somewhat less potent. The results indicate that there is discrimination between the isomers of these compounds at the level of the responding tissue. 相似文献
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Anna Kats Natalija Gerasimcik Tuomas Nreoja Jonas Nederberg Simon Grenlv Ekaterina Lagnhed Suchita Desai Gran Andersson Tülay Yucel‐Lindberg 《Journal of cellular and molecular medicine》2019,23(2):1152-1163
Inflammatory mediator prostaglandin E2 (PGE2) contributes to bone resorption in several inflammatory conditions including periodontitis. The terminal enzyme, microsomal prostaglandin E synthase‐1 (mPGES‐1) regulating PGE2 synthesis is a promising therapeutic target to reduce inflammatory bone loss. The aim of this study was to investigate effects of mPGES‐1 inhibitors, aminothiazoles TH‐848 and TH‐644, on PGE2 production and osteoclastogenesis in co‐cultures of periodontal ligament (PDL) and osteoclast progenitor cells RAW 264.7, stimulated by lipopolysaccharide (LPS), and bone resorption in RANKL‐mediated peripheral blood mononuclear cells (PBMCs). PDL and RAW 264.7 cells were cultured separately or co‐cultured and treated with LPS alone or in combination with aminothiazoles. Multinucleated cells stained positively for tartrate‐resistant acid phosphatase (TRAP) were scored as osteoclast‐like cells. Levels of PGE2, osteoprotegerin (OPG) and interleukin‐6, as well as mRNA expression of mPGES‐1, OPG and RANKL were analysed in PDL cells. PBMCs were treated with RANKL alone or in combination with aminothiazoles. TRAP‐positive multinucleated cells were analysed and bone resorption was measured by the CTX‐I assay. Aminothiazoles reduced LPS‐stimulated osteoclast‐like cell formation both in co‐cultures and in RAW 264.7 cells. Additionally, aminothiazoles inhibited PGE2 production in LPS‐stimulated cultures, but did not affect LPS‐induced mPGES‐1, OPG or RANKL mRNA expression in PDL cells. In PBMCs, inhibitors decreased both osteoclast differentiation and bone resorption. In conclusion, aminothiazoles reduced the formation of osteoclast‐like cells and decreased the production of PGE2 in co‐cultures as well as single‐cell cultures. Furthermore, these compounds inhibited RANKL‐induced bone resorption and differentiation of PBMCs, suggesting these inhibitors for future treatment of inflammatory bone loss such as periodontitis. 相似文献
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J. Taura M. Valle‐León K. Sahlholm M. Watanabe K. Van Craenenbroeck V. Fernández‐Dueñas S. Ferré F. Ciruela 《Genes, Brain & Behavior》2018,17(4)
G protein‐coupled receptors (GPCR) exhibit the ability to form receptor complexes that include molecularly different GPCR (ie, GPCR heteromers), which endow them with singular functional and pharmacological characteristics. The relative expression of GPCR heteromers remains a matter of intense debate. Recent studies support that adenosine A2A receptors (A2AR) and dopamine D2 receptors (D2R) predominantly form A2AR‐D2R heteromers in the striatum. The aim of the present study was evaluating the behavioral effects of pharmacological manipulation and genetic blockade of A2AR and D2R within the frame of such a predominant striatal heteromeric population. First, in order to avoid possible strain‐related differences, a new D2R‐deficient mouse with the same genetic background (CD‐1) than the A2AR knock‐out mouse was generated. Locomotor activity, pre‐pulse inhibition (PPI) and drug‐induced catalepsy were then evaluated in wild‐type, A2AR and D2R knock‐out mice, with and without the concomitant administration of either the D2R agonist sumanirole or the A2AR antagonist SCH442416. SCH442416‐mediated locomotor effects were demonstrated to be dependent on D2R signaling. Similarly, a significant dependence on A2AR signaling was observed for PPI and for haloperidol‐induced catalepsy. The results could be explained by the existence of one main population of striatal postsynaptic A2AR‐D2R heteromers, which may constitute a relevant target for the treatment of Parkinson's disease and other neuropsychiatric disorders. 相似文献
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《Journal of cellular and molecular medicine》2017,21(5):975-985
This study aims to explore effects of 1,25(OH)2D3 and vitamin D receptor (VDR) on peripheral CD4+/CD8+ double‐positive (DP) T lymphocytes in systemic lupus erythematosus (SLE). MRL‐LPr/LPr mice with SLE (n = 20) and normal MRL mice (n = 20) were assigned into the control group (normal mice, without feeding with 1,25(OH)2D3), the 1,25(OH)2D3 group (SLE mice, feeding with 1,25(OH)2D3), the VDR‐knock‐in + 1,25(OH)2D3 group (SLE mice, VDR‐knock‐in, feeding with 1,25(OH)2D3) and the VDR‐knockout group (normal mice, VDR‐knockout, without feeding with 1,25(OH)2D3) (n = 10 per group). Levels of T lymphocytes were measured by flow cytometry. The mRNA and proteins expressions of inflammatory factors were measured by qRT‐PCR and ELISA. Extracellular signal‐regulated kinase‐1/2 (ERK1/2) expression was measured by Western blotting. Compared with normal mice, SLE mice showed reduced levels of CD4+, CD4+/CD8+ ratio, and DP lymphocytes. The levels of SLE‐related indicators all increased significantly, followed with severe skin ulcers and urinary system infection. With the increase in time, skin ulcers and urinary system infection were significantly improved, levels of CD4+, CD4+/CD8+ ratio, and DP lymphocytes increased, and levels of SLE‐related indicators all decreased in the 1,25(OH)2D3 group. There were no significant changes in bioindicators in the control and the VDR‐knock‐in + 1,25(OH)2D3 groups. The symptoms of SLE gradually occurred in the VDR‐knockout group. This study demonstrates that VDR and 1,25(OH)2D3 could elevate CD4+/CD8+ DP T lymphocytes and reduce expressions of inflammatory factors, thus inhibiting the development and progression of SLE. 相似文献
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Objective: Obesity is associated with elevated oxidative stress and low‐grade systemic inflammation. We have demonstrated recently that 1α,25‐(OH)2‐D3 promotes reactive oxygen species production in cultured adipocytes, whereas suppression of 1α,25‐(OH)2‐D3 by increasing dietary calcium down‐regulates diet‐induced oxidative stress in aP2‐agouti transgenic mice. However, whether the anti‐obesity effect of dietary calcium plays a role in regulation of obesity‐associated inflammation is not clear. Research Methods and Procedures: We investigated the role of dietary calcium in the regulation of inflammatory cytokine production in aP2‐agouti transgenic mice fed low‐ and high‐calcium obesigenic diets and in the modulation of cytokine production by 1α,25‐(OH)2‐D3 in cultured murine and human adipocytes. Results: The high‐calcium diet inhibited the expression of pro‐inflammatory factors tumor necrosis factor α and interleukin (IL)‐6 by 64% and 51%, respectively (p < 0.001), in visceral fat, stimulated the expression of the anti‐inflammatory factors IL‐15 and adiponectin by 52% (p = 0.001) and 54% (p = 0.025), respectively, in visceral fat, and induced a 2‐fold increase in IL‐15 expression in soleus muscle (p = 0.01) compared with litter mate controls on a low‐calcium diet. 1α,25‐(OH)2‐D3 also markedly stimulated the expression of tumor necrosis factor α (p < 0.001) and IL‐6 (p = 0.016) in differentiated 3T3‐L1 adipocytes and increased IL‐6 (p = 0.004) and IL‐8 (p < 0.001) production in differentiated human adipocytes. These effects were blocked by calcium channel antagonism with nifedipine. Discussion: These data demonstrate that 1α,25‐(OH)2‐D3 favors inflammatory cytokine expression and inhibits anti‐inflammatory cytokine expression; accordingly, suppression of 1α,25‐(OH)2‐D3 by dietary calcium inhibits adipocyte‐derived inflammation associated with obesity. 相似文献
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Tanya Dossa Alice Arabian Jolene J. Windle Shoukat Dedhar Steven L. Teitelbaum F. Patrick Ross G. David Roodman René St‐Arnaud 《Journal of cellular biochemistry》2010,110(4):960-967
Bone resorption requires the adhesion of osteoclasts to extracellular matrix (ECM) components, a process mediated by the αvβ3 integrin. Following engagement with the ECM, integrin receptors signal via multiple downstream effectors, including the integrin‐linked kinase (ILK). In order to characterize the physiological role of ILK in bone resorption, we generated mice with an osteoclast‐specific Ilk gene ablation by mating mice with a floxed Ilk allele with TRAP‐Cre transgenic mice. The TRAP‐Cre mice specifically excised floxed alleles in osteoclasts, as revealed by crossing them with the ROSA26R reporter strain. Osteoclast‐specific Ilk mutant mice appeared phenotypically normal, but histomorphometric analysis of the proximal tibia revealed an increase in bone volume and trabecular thickness. Osteoclast‐specific Ilk ablation was associated with an increase in osteoclastogenesis both in vitro and in vivo. However, the mutant osteoclasts displayed a decrease in resorption activity as assessed by reduced pit formation on dentin slices in vitro and decreased serum concentrations of the C‐terminal telopeptide of collagen in vivo. Interestingly, compound heterozygous mice in which one allele of Ilk and one allele of the β3 integrin gene were inactivated (ILK+/?; β) also had increased trabecular thickness, confirming that β3 integrin and Ilk form part of the same genetic cascade. Our results show that ILK is important for the function, but not the differentiation, of osteoclasts. J. Cell. Biochem. 110: 960–967, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
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Karen van der Meijden Paul Lips Marjolein van Driel Annemieke C. Heijboer Engelbert A. J. M. Schulten Martin den Heijer Nathalie Bravenboer 《PloS one》2014,9(10)
The most biologically active metabolite 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has well known direct effects on osteoblast growth and differentiation in vitro. The precursor 25-hydroxyvitamin D3 (25(OH)D3) can affect osteoblast function via conversion to 1,25(OH)2D3, however, it is largely unknown whether 25(OH)D3 can affect primary osteoblast function on its own. Furthermore, 25(OH)D3 is not only converted to 1,25(OH)2D3, but also to 24R,25-dihydroxyvitamin D3 (24R,25(OH)2D3) which may have bioactivity as well. Therefore we used a primary human osteoblast model to examine whether 25(OH)D3 itself can affect osteoblast function using CYP27B1 silencing and to investigate whether 24R,25(OH)2D3 can affect osteoblast function. We showed that primary human osteoblasts responded to both 25(OH)D3 and 1,25(OH)2D3 by reducing their proliferation and enhancing their differentiation by the increase of alkaline phosphatase, osteocalcin and osteopontin expression. Osteoblasts expressed CYP27B1 and CYP24 and synthesized 1,25(OH)2D3 and 24R,25(OH)2D3 dose-dependently. Silencing of CYP27B1 resulted in a decline of 1,25(OH)2D3 synthesis, but we observed no significant differences in mRNA levels of differentiation markers in CYP27B1-silenced cells compared to control cells after treatment with 25(OH)D3. We demonstrated that 24R,25(OH)2D3 increased mRNA levels of alkaline phosphatase, osteocalcin and osteopontin. In addition, 24R,25(OH)2D3 strongly increased CYP24 mRNA. In conclusion, the vitamin D metabolites 25(OH)D3, 1,25(OH)2D3 and 24R,25(OH)2D3 can affect osteoblast differentiation directly or indirectly. We showed that primary human osteoblasts not only respond to 1,25(OH)2D3, but also to 24R,25(OH)2D3 by enhancing osteoblast differentiation. This suggests that 25(OH)D3 can affect osteoblast differentiation via conversion to the active metabolite 1,25(OH)2D3, but also via conversion to 24R,25(OH)2D3. Whether 25(OH)D3 has direct actions on osteoblast function needs further investigation. 相似文献
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Timothy A. Reinhardt Ronald L. Horst E.Travis Littledike Donald C. Beitz 《Biochemical and biophysical research communications》1982,106(3):1012-1018
1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] receptor was characterized after partial purification of thymus cytosol by ammonium sulfate fractionation. The 1,25-(OH)2D3 receptor sediments at 3.7S in 5–20% sucrose gradients. The binding of 1,25-(OH)2D3 in thymic cytosol was a saturable process with high affinity (Kd = 0.12?0.48 nM) at 4°C. Competition for 1,25-(OH)2[3H]D3 receptor by nonradioactive analogs demonstrated the affinities of these analogs to be in order; 1,25-(OH)2D3 = 1,24R,25-(OH)3D3 = 1,25S,26-(OH)3D3 = 1,25R,26-(OH)3D3 > 1,25-(OH)2D3-26,23 lactone > 25-OHD3 > 23R,25-(OH)2D3 > 24R,25-(OH)2D3 > 23S,25-(OH)2D3 ? 25-OHD3-26,23 lactone. The receptor bound to DNA cellulose columns in low salt buffer and eluted as a single peak at 0.21 M KCl. These findings provide evidence that the thymus possesses a 1,25-(OH)2D3 receptor with properties indistinguishable from 1,25-(OH)2D3 receptors in other tissues. 相似文献
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Tarik Dahoun Matthew M. Nour Rick A. Adams Svenja Trossbach Sang H. Lee Hamel Patel Charles Curtis Carsten Korth Oliver D. Howes 《Genes, Brain & Behavior》2019,18(8)
The disrupted‐in‐schizophrenia 1 (DISC1) protein has been implicated in a range of biological mechanisms underlying chronic mental disorders such as schizophrenia. Schizophrenia is associated with abnormal striatal dopamine signalling, and all antipsychotic drugs block striatal dopamine 2/3 receptors (D2/3Rs). Importantly, the DISC1 protein directly interacts and forms a protein complex with the dopamine D2 receptor (D2R) that inhibits agonist‐induced D2R internalisation. Moreover, animal studies have found large striatal increases in the proportion of D2R receptors in a high affinity state (D2highR) in DISC1 rodent models. Here, we investigated the relationship between the three most common polymorphisms altering the amino‐acid sequence of the DISC1 protein (Ser704Cys (rs821616), Leu607Phe (rs6675281) and Arg264Gln (rs3738401)) and striatal D2/3R availability in 41 healthy human volunteers, using [11C]‐(+)‐PHNO positron emission tomography. We found no association between DISC1 polymorphisms and D2/3R availability in the striatum and D2R availability in the caudate and putamen. Therefore, despite a direct interaction between DISC1 and the D2R, none of its main functional polymorphisms impact striatal D2/3R binding potential, suggesting DISC1 variants act through other mechanisms. 相似文献
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Stephen Ching Soumya Kashinkunti Matthew D. Niehaus Glendon M. Zinser 《Journal of cellular biochemistry》2011,112(11):3393-3405
The vitamin D3 receptor (VDR) is present in all microenvironments of the breast, yet it is hypothesized to signal through the epithelium to regulate hormone induced growth and differentiation. However, the influence or contribution of the other microenvironments within the breast that express VDR, like the breast adipose tissue, are yet to be investigated. We hypothesized that the breast adipocytes express the signaling components necessary to participate in vitamin D3 synthesis and signaling via VDR, modulating ductal epithelial cell growth and differentiation. We utilized human primary breast adipocytes and VDR wild type (WT) and knockout (KO) mice to address whether breast adipocytes participate in vitamin D3‐induced growth regulation of the ductal epithelium. We report in this study that breast primary adipocytes express VDR, CYP27B1 (1α‐hydroxylase, 1α‐OHase), the enzyme that generates the biologically active VDR ligand, 1α,25‐dihydroxyvitamin D3 (1,25D3), and CYP24 (24‐hydroxylase, 24‐OHase), a VDR‐1,25D3 induced target gene. Furthermore, the breast adipocytes participate in bioactivating 25‐hydroxyvitamin D3 (25D3) to the active ligand, 1,25D3, and secreting it to the surrounding microenvironment. In support of this concept, we report that purified mammary ductal epithelial fragments (organoids) from VDR KO mice, co‐cultured with WT breast adipocytes, were growth inhibited upon treatment with 25D3 or 1,25D3 compared to vehicle alone. Collectively, these results demonstrate that breast adipocytes bioactivate 25D3 to 1,25D3, signal via VDR within the adipocytes, and release an inhibitory factor that regulates ductal epithelial cell growth, suggesting that breast adipose tissue contributes to vitamin D3‐induced growth regulation of ductal epithelium. J. Cell. Biochem. 112: 3393–3405, 2011. © 2011 Wiley Periodicals, Inc. 相似文献
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Shen Tong Hongji Liu Hui Cheng Chen He Yu Du Ziwei Zhuang Ping Qiu Ke Wang 《Journal of biophotonics》2019,12(6)
Three‐photon microscopy excited at the 1700‐nm window (roughly covering 1600‐1840 nm) is especially suitable for deep‐brain imaging in living animals. To match the brain refractive index, D2O has been exclusively used as the immersion medium. However, the hygroscopic property of D2O leads to a decrease of transmittance of the excitation light and as a result a decrease in three‐photon signals over time. Solutions such as replacing D2O from time to time, wrapping both the objective lens and the immersion D2O, and sealing D2O with paraffin liquid have all been demonstrated, which add to the system complexity. Based on our recent characterization of immersion oils, we propose using silicone oil as a potential alternative to D2O for deep‐brain imaging. Excited at 1600 nm, our comparative deep‐brain imaging using both D2O and silicone oil immersion show that silicone oil immersion yields 17% higher three‐photon signal in third‐harmonic generation imaging within the white matter. Besides, silicone oil immersion also enables three‐photon fluorescence imaging of vasculature up to 1460 μm (mechanical depth) into the mouse brain in vivo acquired at 2 seconds/frame. Together with the nonhygroscopic physical property, silicone oil is promising for long‐span three‐photon brain imaging excited at the 1700‐nm window. 相似文献